Air-driven impeller



April 24, 1951 R, B COTTON 2,550,229

AIR DRIVEN IMPELLER Filed Aug. 26, 194e 5 sheets-sheet 1 @5527 5. ovv-OMApril 24, 1951 R. B. COTTON AIR DRIVEN IMPELLER 5 Sheets-Sheet 2 FiledAug. 26, 1946 I NVENTOR.

7065er f5 COTTOM ///5 ATTOZA/Ef April 24, 1951 v R, B, COTTON 2,550,229

AIR DRIVEN IMPELLER Filed Aug. 26, 1946 5 Sheets-Sheet 3 INVENTOR. @55575- Corfo/V April 24, 1951 R B. COTTON 2,550,229

AIR DRIVEN IMPELLER Filed Aug. 2e, 194e 5 sheets-sheet 4 April 24, 1951R. B. COTTON 2,550,229

AIR DRIVEN IMPELLER Filed Aug. 26, 194e 5 'sheets-sheet 5 INVENTOR.Fog/96T 5. 60 T TOM Patented pr. 24, 1951 i UNITED STATES 'PATENT OFFICEY* AIR-DRIVEN IDIPELLER v Robert B.y Cotton, Lansdowne, Pa., assigner toAll American Delaware Airways, Inc., a corporation of Y ApplicationAugust 26, 1946, Serial No. 693,044

This invention relates to air driven impellers such as are intended tobe mounted on aircraft for the purpose of generating power and Visconcerned primarily with certain `4improvements de- .signed tofacilitate adjustment to develop varying degrees of power and increasethe conditions of safety with which such impellers vmay be used.

Due .toA recent Vdevelopments in the iield of aircraft, particularlyinthe picking up Vand towingv .of gliders, it becomes necessary to haveavailable` on the aircraft a source Vofpowerwhch willdevelopconsiderable: power. Such power is needed in the reeling in of glidertowlines and when it fis considered that under manyconditions a heavygliderisatthe other endof a tow line, a large` amount of horsepower is`required. A.While -it might be possible to provide an electricinstallationv for generating this power, the large number of horsepowerwouldrequire such a heavy' installation as to render it undesirable inaircraft Where weight is Va great factor. Accordingly,it has been thepractice to employ air driven impellers which derive the power from theforward movement of the plane and which are capable of generating a highdegree of horsepower with comparatively light installations. The presentinvention deals with improvements in such air driven impellersl y `Animportant..,object `of theV invention is the Aprovision of an air-drivenVimpcller including vanes of adjustable pitch -which may be adjusted vtoderive any power from zerol upto a maximum.

rllhe zero development is created when the vanes are fully feathered andthe maximum is that langular position of the .blades at which full poweris. developed. By providing appropriate mechanism for adjusting thepitch ofv thek blades any required amount of power may be developedrover this range as occasion demands.

Air driven impellers of the type with which this invention is concernedinclude vanes which are driven at a high rate of speed, often attaininga speed of rotation in the neighborhood of fourthousand revolutions aminute. When the impeller is properly loaded there is no particulardanger, but should the load rapidly diminish or be entirely taken offthe impeller, there is gravek danger o f theY highspeed rotationwrecking the vmechanism byv centrifugal force and this is, of

course,` attendedby a possibility of injury to personnel.

Accordingly, a highlyimportantv object of the invention is the provisionof an air driven imf Claims. (01.,170-62) vanesrwhen a certainpre-determined speed of rotation is exceeded. f l

Yet,` another object of the invention is the provision, in-a-nair drivenimpeller of thetype indicated, .of means for varying thespeed at whichthe blades will automatically feather.

Other more detailedobjects andadvantages v of ltheinvention'wiH vinlpart. becomeappafrent :ing the precepts of this inventonshown with partsbroken away.` This View also .develops the and inpart behereinafterstated as'thevdes'cription of the invention proceeds. g

The invention therefore `comprises an air driven impellerincludingadjustable pitchbl'ades, together with mechanism for adjusting the pitchof the blades to develop the degree of power required andrmeans forcausing the blades to automatically feather when a certainpredeterminedsafe speed of rotation is exceeded.

For a full and more complete understanding of the invention, referencemay be. had to the Agfollowing description `and accompanying drawingswherein; Y

'Figure 1 is a sideview of an impeller embodycontrol lever kwhichgoverns the amount of. power ,developed andwhichmay be located,` at`a`point remote from the impelleritself.

. Figureais a, section takenihroughlnf peller mechanismproper. 1

Figure .Sis an enlarged detail showing mostly in section. bringing outthe governor and associated mechanism for causing theA automatic y jFigure 5 is a detailed viewtaken as a `through the end of the impellerat whichthevanes Figure 4 is.` another view similar to Figure showingtheposition of thel parts after the fully,

feathered condition is. established..

section varelo'catedg This view brings out the positionpellerinclu'dingadjustable pitch blades, together with means forautomatically:f-eathering vthe 'peller of 'this invention is shown as.comprising 4the :mechanism proper and the control therefor.The"`mechanism which actually develops the K .power is :preferablymounted on a wing ofthe Vaircraft'on' which the impeller `is assembled.

' ange 'I4 which is in abutting relation with a solid ring-likestructure I5 which is formed as an integral part of the casing sectionI2. Screw bolts shown at I6 secure the fiange I4 `andvring f5 together.The tailpiece I3 is ailixed to the casing section I2 by screwfasteningelements shownat I'I. The nosepiece I I rotates with respect tothe remainder of the casing structure and is secured in proper positionrelative theretobymechanism to be hereinafter described.

Referring again to Eigure 1, the control for ...adjusting the pitch ofthe vanes is identified in "its entirety by the reference character C.'This control may be located at any convenient Vlocation Lintheiuselageofthe plane. It comprisesja pair `of spa'ced panels I8 and I9which are 'held in properlassembled relation vbythe required number ofbolts26 and spacer sleeves 2I.v These panels '"I'andl VIli'are anchoredin adesired'loca'tion. A Vcontrol lever 22 'pof'tubular `formationreceives in Vits "lower 'end thereduced end of a solid element 23y whichis pivotally mounted at '24 between the panels .I6 and I9. The 'lowerend of this solid 'member 23 is bifurcated as shown at 25, andre-Vceived in the fork construction is the fiat end 26 of aiiexiblepush-rod'21. vPivot pin 28 establishes Hlthe'connection Vbetween-theflexible push rod 21 andthe control 'lever 22. ThisY flexible'push rod21 passes through a guide 29 vmounted between therpanels I8 and I9 andextends up 'into the wstandard I0.

A'ratchet segment 30 is mounted on the panel construction and thissegment presents ratchet teeth 3l in a'downwardly exposed position.Conltrol rod Y22 is slotted'as indicated-at 32 toreceive VV'the ratchetVsegment 30. A plunger 33 ispo- :sitioned within'the tubular control rod22 and carries a pointed tooth .34 which normally engages .one of theratchet Ate'ethSI. An expansion coil spring bears against the solidmember 23 nat one end, and the other Lend'is rendered effectivey againstlthe pointed 'tooth34 to yieldably urgefthe latter .into engagement withthe ratchet teeth. 'A handle is shown in the form of a round knob 1.36and .this handle is mounted on the `upper .end

ofthe tubular vcontrol rod 22. This knob 36 -is formedwith an axialpassage in 4alignment with a .bore of the tube 22. The plunger33 has areduced portion '31 received in .this axialpassage and carries at `itsfree end a push tab .38. It is evident that the operator may grasp theknob .36

with his hand and at the same time Vwith .his thumb depress the Vtab 38.This pushes the tooth T34 downwardly against the inuence of the spring35 and releases it from engagement with the formed with a main journal40 which may be of the hollow construction indicated to keep weight downto a minimum. This section I2 also carries a second journal construction4I adjacent to the tail, and it is these journals 40 and 4I whichoperatively support the main shaft 42, there being various partsinterposed Ybetween the journals and ltheshaft.

Received in the tubular bore of the journal 40 is a cylindrical sleeve43 having an end iiange 44 which abuts the front end of the journal 40.A

`retaining ring 45 in turn abuts the fiange 44 and screw bolts 46securely clamp both the retaining ring 45 andthe flange 44 to thejournal construction 40.

It will be noted that the shaft 42 carries an .enlargement `in the formof a spacer ring 41.

Rotatively mounted with respect to the shaft 42 is a driving sleeve 48which fits over the enlargement 41. Bearing assemblies 49 and 50 are.in-

v'terp'osed vbetween `the sleeve 43 and the driving sleeve Y48.

An oil seal is shown at 5I as being Aheld in position by the retainingring 45.. Cooperatingwith this oil seal 5I is aring 52 which snugly fitsabout the driving sleeve 48. A spacer ring shown at 53 serves tomaintain the bearing assemblies 49 Vand 56 in properly spaced relation.VThe `inner end of thev driving sleeve 48 -termiifnates in a bevel gear54 which, ofcourse, surlratchet. teeth. The control lever may nowbe amechanism which .actual-1y developsv the power,

'will' be described. The main casing section 'I2 is designated as 56.

A'are more clearly Ashown inFigure 7 at 69.

roundsV theshaft 42. This bevel gear 54 meshes 'with acomplemental'bevel gear 55 which is carried at the upper -end of a powertake-off shaft The latter is journaled on bearing assemblies 51 and 58whichzin'turn are supported by the vring-like structurei59 which isboltedY to the casing I2. The power take-oil shaft 56 extends downwardlythrough the stand- 'ard IU'and at its lower end vmay be operatively Y'`snugly fitted Awithin the shell-like nose I I is ay hub member 69.Screw fastening elements shownV at 6I establish a 'permanent connectionbetween the nose and the hub. vThe driving vvvAsleeve 48 is keyed to thehub 6I] asshown at 62.

The hu-b 60 carries a plurality of adjustable Apitch lblades. 4Forillustrative purposes, it may be assumed that there lare'threesuchjblades although this number maybe `varied. as occasion demands.YInasmuch as these vblades :are substantial duplipates,y it 'isnecessary to describe only one of them for the purpose of thisspecication. Such a blade'or vane i's shown at 63 and includes a reducedneck 64 of cylindrical formation which extendsjinto the hub. The hub 60is formed Iwith a recess to accommodate the reduced neck V64 of eachvane.

A bearing assembly shown at is mounted in each recess and is interposedvbetween the reduced neck 64 and the hub VIii). The inner end of eachneck 64 drivably carries a bevel gear 66. This gear '66 .meshes with acomplemental bevel Vgear 61 which is carried at `one end of a sleeve 68that 'isrotatively mounted on the Ishaft 42. The sleeve 68 is formedwith Vajpair 'of oppositely disposed .helical slots which VThese 'slotsare also shown in dotted lines in vFigure 2. An actuating pin 10 iscarried bythe shaft 42 and has its ends received in the slots '69. 'TheAshaft 42 is .held against rotation with respect to the 'hub V6 6 aswilllbe later described. Thus,

upon .rectilinearmovement of the shaft'42 the pin 'III will causerelative rotation of the sleeve autogas l 68 with respectthereto. Thisin turn drives the lbevelgear 61 and through the bevel gear 66 i`adjusts the pitch of the blade 63.

The hub 60 is cut away to provide a recess which accommodates the bevelgears 66 and 61. The recess is closed by a cap 1I that is bolted to thehub 60 as shown at 12. This cap 1| includes a cylindrical extension 13in which the shaft 42 is received. The latter is slotted as shown at 14and a pin 15 is received in this slot. The ends of this pin are anchoredin the extension.13. It is this pin and slot construction which preventsrelative rotation of the hub 60 and the shaft 42. Vflitted over theextension-13v is a spring retainer 16 and ttedover the latter is anexpansioncoil spring? 1-1. The latter bears against van end plate 18which is anchored to the shaft v42 by the screw bolt 19. Itis evidentthat the normal tendency of the spring 11 is to urge the `shaft 42forwardly into the nosepiece.

Referring now more particularly to Figures 3 and 4, the mechanism forcontrol of the rectilineal movement of the shaft 42 will be described.The tail end of the shaft 42 carries van enlargement 80 which presents ashoulder 8I.` A collapsible sleeve which is shown in detail in Figure 6isvdesignated 82. This sleeve 82 has at its tail end a hub structure 83formed with a shoulder 84 which abuts the shoulder 0I. The sleeve 83also has an external shoulder 85(Figure 6) against which abuts agovernor plate 86. Washers 81 are mountedon the shaft 42 and bearagainst the tail end of the sleeve 82 and the governor plate 86. A nut8B is 'screwed on to threads 89 which are formed on the end ofthe shaft42. This nut serves to securely clampthe sleeve 82 into position withits shoulder 84 abutting the shoulder 8|"on the shaft and also positionsthe vgovernor .plate 86. The sleeve 82 is formed with a plurality of'slots 90 (seeFigin'e` 6) which extend inwardly 'fromthe forward end. ofthe sleeve and these slotsrender the sleeve of the collapsible nature.The structure between the slots might properly `be described as'springfingers which `are capable of being collapsed inwardly. Adjacent the`inner end, the sleeveA 82 is reduced in diametric dimension to provide ashoulder 9| which normally engages a complemental shoulder on a bearingassembly 92. The latter is positioned within a cup-shaped extension 93that is formed as an integral part of an actuating sleeve 94. This cupshaped extension is slidably received in the journal construction 4| andit will be noted from Figure 2 thatr the-actuating sleeve 94 is disposedin spacedV relation about the shaft 42. The sleeve 94- is provided witha pair of spaced ringllike flanges 95. A bell crank which is referred toin its. entirety by .the reference character B is pivotally-mounted on apin 96 to structure carried as a part of casing I2. One arm of thisVbell crank takes the form of a fork 91, the extremities of which arevreceived between the flanges 95. The other end of the bell crank 98 hasan extremity 99 which is operatively received in a recess |00 formed ina member IOI, carried at the effective free end of the exible push rod21. Thus, the push rod 21 may be availed of to actuate the -bell crankB. Such movement in turn through the connection of the fork arm 91 andflanges 95 imparts rectilineal movement to the actuatingsleeve 94. Ifthis movement is towards the tail, it will be resisted by the spring 11because of the engagement of the shoulder A9| -with the bearing assembly92. Movement of the sleeve 94 and shaft 42 toward the nose is, ofcourse, aided and caused by the spring 11.

Referring now more 'particularly to vFigure 6, it will Vbe vnoted thatthe sleeve 82 intermediate its extremities is formed with a radialenlargement in the form of a ring |02. Adjacent to its outer peripheraledge, the tailpiece of this ring 02 is'slightly dished as shown in |03(see Figurep) whereby it is adapted to function as aspring retainer.lBetween the ring |02 and its solid end, the sleeve 82 is formed with aconical surface |04 for a purpose now to be described. A governor sleeveI 05 is slidably mounted over the sleeve B2l and its free end is formedwith a conical Vbore complemental to the surface |04. The outercylindrical surface of the governor sleeve |05 is threaded as shown at|06 and screwed on to this threaded surface is a spring retainer |01. Anexpansion coil spring |08 is interposed between the surface |03 of thering |02 4and the spring retainer |01. This spring I 08 resists forwardmovement of the governor sleeve |05. The degree of this resistance maybe varied by 'adjusting the spring retainer |01 .on the threads |06.

The tail-end of the governor sleeve |05 is reduced in diameter wherebyit is adapted to receive and carry a ring |09 having a flange |I0. Thegovernor plate 86 is formed with a plurality of ears. II and pivotallymounted on each ear as by a pin shown at I I2, is a bell crank governorelement |I3 having an arm |I4 which extends into engagement with theflange IIO. It is evident thatl as the speed of rotation of the shaft 42increases, the main arms of the bell crank I3 move radially outwardlyunder centrifugal force. This causes the arms I|4 to be moved towardsthe-nose. Thus, the governor sleeve |05 is urged forwardly until such apoint as the resistance of the spring |08 is overcome, whereupon theconical bore of the governor sleeve |05 acting on the conical surface I04 of the sleeve 82 collapses the forward end of the latter. Thus, theshoulder 9| is disengaged from the bearing assembly 92 and the spring 11is rendered effec- A'tive to move'the shaft 42 forwardly and bringforegoing description of the various mechanical assemblies, it may benoted that under a condition of no power development the blades 63 4are,fully feathered.

Should the operator be desirous of developing power, he thereupon.grasps the Vhandle knob 36 of the control and moves the lever 22 in acounterclockwise direction. This exerts a pull on the flexible rod 211.

This moves the arm 98 of the bell crank B downwardly causing movement ofthe forked arms 91 towards the tail. This moves the actuator sleeve 94in the same direction and due to the engagement of the shoulder 9| withthe bearing assembly 92, the shaft 42 is moved toward the tail. Thus,the pin 10 is moved in the helical slot 69 and causes rotation of thesleeve 68 relative to the hub 60. This relative rotation is transmittedthrough the bevel gears 61 and 66 to the blades 63 whereby the pitch ofthe latter is adjusted to develop the required degree of power. Any timethe power developed is to be increased, the lever 22 of the control ismoved in a counterclockwise direction and any time it is to bedecreased, it is moved in a clockwise direction. l

Should a condition of no load or a Vrapidly diminishing rload developand the speed of vrotation of the hub '60 exceed a predetermined safelimit, the governor mechanism is brought into play. As above described,this mechanism causes a collapse of the sleeve 82 whereupon the shoulder`9i is disengaged from the bearing assembly 02 and the spring 11rendered effective to move the shaft 42 into the nose and automaticallybring the blades 63 into a fully feathered posif tion. The point atwhich the impeller will automatically feather may be adjusted by varyingthe tension of the yspring |08 which is accom- Aplished vbyadjusting'the position of the spring retainer |01 on the governor sleeve`|05.

While a preferred specific embodiment of the -invention is hereinbeforeset forth, it is to be clearly understood that the invention is not toVbe limited to the exact construction illustrated and described becausevarious modifications of these details may be provided in putting theinvention into practice within the purview of the vappended claims.

What is claimed is:

l. In an impeller of the character described, supporting structureincluding a casing, a nose rotatable with respect to said casing, a hubin saidV nose, a power take-off in said casing, driving connectionsbetween said hub and said power take-oi, adjustable pitch blades carriedby said hub, 'a longitudinally movable shaft extending =through said huband journaled in said casing, means operatively connectingA said shaftto said blades whereby longitudinal movement of said shaftadjuststhepitch of said blades, an abutment element carried by saidshaft, a collapsi- .blesleeve normally in -engagement with said abutmentelement, spring means normally urging said shaft in a direction opposedby the engagement of said abutment element and said oollapSibIesleeVe,and governor mechanism for causing said sleeve to collapservandpernlitmove- Iment of said shaft under'the influence of said springmeans when va certain predetermined .speedV of rotation is exceeded.

2. In .an impeller of the character described, lsupporting structureincluding -a casing, a nose rotatable 'with respect to said casing, ahub in said nose, a power take-.oi in said casing, driving connectionsbetween said hub and said power take-off, adjustable pitch bladescarried by said hub, a longitudinally movable shaft extending throughsaid hub `and journaled in said casing, means operatively connectingsaid shaft to said `blades whereby 'longitudinal movement of said shaftadjusts the pitch of said blades, an abut#- 'm'ent element carried bysaid shaft, a collapsible Sleeve normally in engagement with saidabutment element, spring means normally urging said shaft in a directionopposed by the engagement .of said Aabutment element and said co1-lapsible sleeve, governor mechanism for causing saidsleeve to collapseand permit movement of said shaft under the influence of said springmeans when a certain predetermined speed of rotation is exceeded, andmeans on said sleeve for varying Vthe predetermined speed at which saidsleeve collapses.

3. In an impeller of the character described, supporting structureincluding a casing, a nose rotatable with respect to said casing, a hubin said nose, a power take-off in said casing, driving connectionsbetween said hub and said power take-off, adjustable pitch bladescarried by said hub, a longitudinally movable shaft extending throughsaid hub and journaled in said casing, means operatively connecting saidshaft to said blades whereby longitudinal movement of said shaft adjuststhe pitch of said blades, actuator means in said casing operativelyconnected to said shaft for causing longitudinal movement thereof toadjust the pitch of the blades, a remote control operatively connectedto said actuator means, a governor mounted on an end ofr said.longitudinally movable shaft, a sleeve connected to said governorlongitudinally shiftable at predetermined speeds of rotation of saidlongitudinally movable shaft, abutment means carried by said shaft, acollapsible member with longitudinally extending iiexible fingersengaging said abutment means and embraced by said governor sleeve forreturning the blades to a fully feathered position when a predeterminedspeed of rotation is exceeded to longitudinally move the lgovernorsleeve thereby displacing said fingers from said abutment means carriedby said shaft, spring means for moving said shaft longitudinally whensaid ngersvdisengage said abutment, a gear with a helically slottedsleeve lmounted onlsaid shaft, a gear carried by each blade engageablewith said rst gear, and a pin `projecting from and carried by said shaftextending into said helical Vslots ofthe said gear sleeve, wherebylongitudinal movement of the shaft moves said pin in the helical slotsand u turns said first mentioned gear engaged with Vle of this patent:

said blade gears to feather the blades.

ROBERT B. COI'ION.

REFERENCES CITED The following references are of record in the UNITEDSTATES PATENTS

